Electromagnetic device



April 10, 1928. 1,665,318

E. D. MEAD ELECTROMAGNETI C DEVICE Filed June 18, 1925 2 Sheets-Sheet l /f Z3 /6 Z Wye/770mfdmrrd .0. Alma April 10, 1928. 1,665,318

E. D. MEAD ELECTROMAGNETIC DEVICE Filed June 18, 1925 2 Sheets-Sheet 2 fill/em: [diva/d 0 Mead Q Patented Apr. 10, 1928.

UNITED STATES PATENT. OFFICE.

EDWARD D. MEAD, OF CALDWELL, NEW JERSEY,.ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF

NEW YORK, N. Y., A. conronA'rIoN orNnw YORK.

ELECTROMAGNETIC DEVICE.

Application filed June 18, 1925. Serial No. 37,956.

This invention relates to electromagnetic devices, and more particularly to electro magnetic relays of the slow release and slow operate type, wherein the operation of an associated means or the establishment of a desired circuit condition, is delayed for a definite interval of time.

Among the objects of the invention is to provide an improved device of this char acter which will function in an accurate manner, during definite intervals, over any desired period of time.

A feature of the invention is the provision of means comprising a balance wheel or an inertia wheel and a retractile spring operated by an electromagnetic device to successively function at predetermined intervals to control a circuit, the closure of which is dependent upon the operation of said device during a finite number of said intervals.

A further feature of the invention is its application to electromagnetic structure wherein a time interval is obtained at each complete movement of an associated inertia wheel. Upon the actuation and return of the wheel, a ratchet mechanism in combination therewith is advanced one step. The time interval of each revolution of the inertia wheel and its return may be accurately controlled and varied as occasion demands. After the ratchet has been stepped a predetermined number of times, a contacting means is closed to control an associated circuit. It is apparent, therefore, that a feature of this structure is the provision of means whose operating character is independent of any fluctuation in currents, since the time interval of each revolution of the inertia wheel is controlled by its retractile spring, which for all practical purposes always remains the same.

A further feature of this invention lies in its application to a relay wherein'a solenoid and plunger type armature are employed. An noid and serves to control the slow operation of a circuit closing device.

A still further feature of the invention whereby a plurality of circuit closing means may be controlled, which in turn govern any associated means dependent upon the closure inertia wheel is associated with the sole-.

of a circuit. By this arrangement, a plurallty of time intervals of varying duration may be measured.

Another feature of the invention coniprises the combination of an electromagnet and a lever arrangement, which controls the movement of an associated inertia wheel. By this means, the operation of a circuit is regulated during a single finite time interyal, dependent on the inertia wheel and the ever.

A better understandin of the invention in its various forms wilf-be had from the following description and appended claims, reference being had to the accompanying drawings wherein,

Figs. 1, 2 and 3 show a relay incorporating one form of the invention whereby a series of identical time intervals are employed to effect the control of a circuit. Fig. 1 is a top plan view of the rela Fig. 2 is a side view taken through the line 2-2 of Fig. 1 and Fig. 3 is a cross-section through the line 3-3 of Fig. 1 showing the associated pawl and ratchet mechanism used in combination with the inertia wheel.

Fig. 4 illustrates the form of the invention wherein a solenoid is associatedwith an inertia wheel device.

Figs. 5 and 6 illustrate the form of the ciple is employed .to control a plurality of contacting means and measure a plurality of different time intervals. Fig. 5 shows the arrangement during both its non-operating condition and while operating. Fig. 6 shows the arrangement in its operated condition.

Fig. 7 shows a simple form of the invention wherein a lever arrangement is associated with an inertia wheel.

While these different forms of the invention, as illustrated, show the application of the principles of the invention in various forms, nevertheless other designs will suggest themselves to one skilled in the art and the invention, therefore is not limited thereto.

Considering Figs. -1, 2 and 3, 1 represents an electromagnet adapted to be energized to attract armature 2. Pin 3 integral with armature 2 is positioned thereon to move in I the slot, as shown, of contact bracket 4 until it reaches the end thereof, when contact bracket 4 will be pulled toward the core This movement, as is I. springs 21 and 22 by of the electromagnet. Contact bracket 1, when pulled. over, due to the action oi pin 3 will cause pin 5 attached to contact bracket 1 to move in notch 6 of spring 17.

irictionally engage pin 5 with the notches of spring 17 so that the contact brackets position is assured by this means. This in turn causes the contact between spring 7 and head 8 of the contact bracket to break. The breaking of this contact will cause the energizing circuit of the electromagnet to be broken and thus allow the armature to restore. The armature 2 in'restoring is aided by spring 9 and upon the completion of its return action will gfiorcibly come in contact with projection 10 of inertia wheel 11 and rotate the wheel counter-clockwise. The inertia wheel can be caused to rotate approximately one revolution, come to rest, and then restore to normal through the action of retractile spring 12. On its return move ment the inertia wheel will revolve clockwise until the projection 10 comes to rest against stop 13. Tt should be noted that pin 14; integral with the inertia wheel is normally incontact with and presses against spring 7 and, hence, assures good contact between the spring and head 8 of contact bracket 1. Thus, upon the return of the inertia wheel, pin 14, will again press against spring 7 and cause the recontacting between spring 7 and contact bracket 4, and once again complete the energizing circuit for the electromagnet.

Ratchet device 15 is associated with the inertia wheel mechanism and upon each revolutionand return of the inertia wheel, pawl 16 will advance the ratchet one step. Retaining means (not shown) is provided to lreep the ratchet in place during successive movements. This cycle of events continues to take place until the pin 13 on the ratchet wheel is advanced suficiently to strike finger 19 of roller bracket 20. This rotates the bracket 20 so that contact springs 21 and 22 are closed to loclr the relay up.

ther contact springs for controlling ear-- ternal circuits may be operated along with the movement of the roller bracket 20. The relay remains in the operated position as long as the current is When the current is removed, the armature restores to'normal through the action or the retractile spring 9, and pawl 16 rides up on pin 23 disengaging itself from the ratchet wheel and holding pawl (not shown); releases the ratchet wheel which restores to normal. This permits spring 241 rotate bracket 20 against stop 25 where= upon the spring contacts are restored to nor Briefly then, the operation consists in actuating a ratchet wheel the forward strolre an armature and rotating an inertia.

illustrated serves to roller arm Spring contacts associated therewith are I 1 provided to control outside circuit condutions.

Considering the device shown in Fig. 4;, 31 represents a plunger adapted to be drawn into solenoid 32 upon the energization thereof. llnertia wheel 33 is associated with plunger 31 by means of string 34: which is attached at one end to the plunger and at the other end to drum 35 of the inertia wheel. Projecting arm 36 is attached and controls 37 which in turn regulates the operation of contact springs 38 and 39. Projection 40 is integral with arm 36 and is adapted to rest against stop 41 of the inertia wheel upon its return to normal.

The dotted lines of the drawing show the various elements of the structure when in operated condition. The operation in brief consists of the attraction of the plunger 31 upon theenergization oi the solenoid whereby wheel 33 is rotated any desired distance through the action oi spring 34: controlled by the plunger. When head d2 of the plungor strikes the end 43 of arm 36, roller arm 37 is caused to rotate so that plunger 44: associated therewith, operates contact springs 38 and 39.

it is readily understood that the springs may be arranged to be either normally opened or normally closed. The relay holds the plunger operated until the current is removed. Upon the deenergization of the relay plunger 31 is restored to normal by the action of rectractile spring 4:5. acting on drum 35 and the string 34. The pin stop 41 attached to the inertia wheel comes back to normal and in striking projection 40 causes the release of roller armature 37 and consequently the restoration or" the contact springs to normal.

Proceeding lay shown in to a consideration of the rel igs. 5 and 6 the solid lines llli) in F ig. 5 show the relay in its nonoperating condition whereas the dotted lines represent the position of its parts during the operation of the device. Figa 6 shows the device in full operated condition. Springs 50 and 51 are arranged to be normally closed whereas springs 52 and 53 are normally open. Lever arm 54 has an associated sliding link device 55 normally in engage t with pin 56 attached to armature 5'3 relay and adapted to be disengaged. mom said pm by pro ection 67 suitably positioned on the structure. Arm 5%- controls the rotation of inertia wheel 58 through the medium of spring 59 one end of which is attached to the arm and the other to the drum of the wheel. Stop 61 integral with the Wheel, normally rests against element 62 and when situated in that position, projection 63 on the periphery of wheel 58 will keep springs 50 and 51 contacting.

Upon the energization of the electromagnet 64 armature 57 is attracted thereto and will pull 'over link 55 due to pin 56 being engaged therewith. This action will obviously cause the rotation of the inertia wheel due to the movement of arm 54 and thereby cause the opening of the normally closed contact between springs 50 and 51 and cause the closure of normally opened contacts between springs 52 and 53. Upon the end of the movement of the armature link 55 will become disengaged from pin 56 due to the head of the link being lifted by projection 57. At the same time the inertia wheel 58 in restoring to its normal position due to the action of itsyretractile spring will pull back arm 54 and associated link 55. Link 55 will now slip over projection 56 and hence not disturb the closed contact between springs 52 and 53. Upon the complete restoration of the inertia wheel, when stop 61 returns to its position against element 62, Projection 62 will again cause the closure 0 the contacts between springs 50 and'51. As a result of this, the circuit depending upon all the springs being closed will now itself be closed to control any other circuit or device associated therewith. It may be noted therefore that by this means a plurality of time intervals which differ from each other are aflorded in effecting the closure of a circuit; the time interval required for closing springs 52 and 53 differing from, that which elapses between the time springs 50 and 51 open until the time they are closed. It is also of note that the intervals obtained are independent of the fluctuations of the energizing current inasmuch as the major interval is regulated by the action of the inertia wheel whose period of operation is practically constant due' to the unvarying nature of the retractile spring. 7

F ig. 7 shows another form of the invention in which an electromagnet controls an associated lever arrangement 71 which in turn governs the action of an inertiawheel 72. Upon the energization magnet, the inertia ,wheel 72 is obviously operated and causes the contacts between of the electrosprings 73 and 74 to break. Upon the deenergization of the electromagnet the inertia wheel reverses and after an interval equal to the time required for the return of the wheel to normal the springs will be brought together again. It is obvious that instead of having the springs normally closed they may be normally open and hence the relay would be one of the slow release type instead of the slow operate type.

It is evident in all of the structures that slow operation or slow release may be effected by the use of inertia wheel as described; and that this operation is not only independent of the fluctuation of the energizing current but is certain and accurate in the utilization of a time factor'in circuit control.

What is claimed is:

1. An electromagnetic device for measuring a time interval by first measuringaplurality of identical time intervals of lesser duration, comprising an electromagnet, an armature associated therewith, an inertia wheel adapted to be rotated by said armature, a ratchet, a circuit controlling device operated by said ratchet, and means operative upon the energization and deenergization of said electromagnet for respectively actuating said ratchet wheel upon the forward stroke of said armature, and rotating said inertia wheel on the backwardstroke thereof, said circuit controlling device being operated after said ratchet wheel is advanced a desired distance.

2. A relay for controlling a circuit during successive time intervals comprising an armature, an electromagnet for controlling said armature, a contact arm operated by said armature upon the energization of said electromagnet, an inertia Wheel operated by said ,armature .upon the deenergization of said electromagnet andv upon the restoration of said armature, means for assuring the complete restoration of said armature, unvarying means for assuring the restoration of said inertia wheel during a desired interval of time, a circuit normally closed, and means for intermittently opening and closing said circuit during successive identical time intervals by the operation of said armature in combinationwith said contact arm and inertia wheel. 4

In witness whereof, I hereunto subscribe my name this 3 day of June, A. D., 1925 DWARD n. MEAD. 

